<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <button id="myButton">点击我</button>
  <script src="button.js"></script>
</body>
<style>
  .box {
    border: 10px solid #000;
    width: 100px;
    height: 100px;
    background: red;
    padding: 10px;
    /* box-sizing: content-box; */
    opacity: 0;
  }
</style>
</html>